Sound-box for talking-machines.



A. FISCHER.

SOUND BOX FOR TALKING MACHINES. APPLICATION FILED JULY 1, 1909.

989,1 39. Patented Apr. 11, 1911.

7 To (all whom it may concern:

ALEX FISCHER, OF KENSINGTON, LONDON, ENGLAND.

SOUND-BOX FOR TALKING-MACHINES.

Specification of Letters Patent.

Application filed July 1, 1909. Serial No. 505,472.

Be it knownthat I, ALEX FISCHER, asubject of the King of England, residing at 8 Maclise road Kensington, in the county of London, England, have invented certain new and useful Improvements in Sound-Boxes forTalking-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others'skilled in the art to which it appert-ains to make and use the same.

This invention relates to bearings for mounting a stylus on sound boxes of talking machines, and has for its object the improvement of the bearings and coacting parts described in my former Patent Number 904,523, November 24, 1908, sound boxes for talking machines] To these ends the invention consists in the details of construction and novel combinations of parts more fully hereinafter disclosed and particularly pointed out in the claim.

In my former patent above, the spindle c is mounted in brackets I) provided with bearing surfaces concentric with the curved portion of said spindle c and the centers of which lie within said spindle. In the present improvement, however, I substitute for these other curved surfaces withtheir centers outside of the spindle c; as will appear below.

Referring to the accompanying drawings forming a part of this specification in which like letters refer to like parts in all the and, Fig. 8, shows a perspective view of the stylus and associated parts.

a is the shell of the sound box provided. with guide bearings b. It will be observed from Figs. ,1 to 7 that these hearings are of concave form, and are a small segment of a circle. a

c is the spindle, hearing which, as in the patentabo've, may be circular or partly circular in cross section.

.In Figs. 2 and 4; the radius of curvature of the spindleis smaller than the radlus of ;eurvature of the guide bearing surface 6,

while in Fig. 5 the radius of curvature of the spindle o is the same as that of theguide bearingsurface b, but in each case the center of the circle, of which the bearingsurface b is the circumference instead of falling within said spindle c, falls'considerably outside the same.

7; shows spiral controlling springs and It shows hollow nuts. 9 is a flat spring preferably attached by a screw to the side of the spindle 0 opposite the bearing surface, the other end being slotted and having a screw 10 passing through such slot into the shell a of the sound box.

Referring now to the form shown in Fig. 3, which is intended more especially for the construction of a cheaper sound box than that described, in this case the springs 7e hollow nuts 72. and brackets 9 shown in Fig. 2 of the drawings of the 4 dispensedwith, and in their place a second flat spring 9 is attached to the side ofthe spindle c opposite its bearing surface as seen on the left of Fi 3.

Referring to the details shown in Figs. 6

and 7 which are edge views of two forms of guide bearings b, the guide bearing shown in Fig. 6 is made of a thin plate, while the gulde bearing in Fig. 7 is made with a beveled bearing also.

From the construction now disclosed, it will be evident since the centers of curvature I of the bearings b and 0 fall outsideof the spindle c, that not only will. all the freedom of motion be permitted that is )ossessed by thecorresponding structure of my patent above, but in addition to such motion the present structure enables the spindle c to have a slight sidewise movement in the bearing 1). In other words said spindle may,

in a sense, be considered as constituting the the patent above would be unsuitable to per- 1 10 mit this lateral shifting of the fulcrum so atent above, are

Patented Apr. 11, 1911.

long as the centers of curvature of the bear- 'ings liev with ;,the spindle c. It isalso evi- -t0 the length of the iever shave dent, if the bearing surface of the part b is made straight, too much play will be allowed the spindle c. In practice I have found a convenient length 01%. rad for the eurx'm ture of the said bearing 10 be about equal of course, this may be vars stroying the heneficiai tion.

What I claim is In stalking machine, the cam a casing; a diaphragm in 1. Of eencavely curved g! with said casing; a spine; curved guide bearings a" with said first mentioned bearings, the cen-' ter of curvature of each of said first mentioned bear ngs being located outslde of said spindle, and the radius of curvature of sald 4 spindle being less than the radius of curvature of said first mentioned bearings; and a stylus bar attached to said diaphragm and spindle, substantially as described.

.In testinion whereof, I aflix my signature,

; in presence 0 two Witnesses. 

